Electric incandescent lamp and holder thereof



Nov. 1, 1932.

E. R. GROTE ELECTRIC INCANDESCENT LAMP AND HOLDER THEREOF Filed Dec. 5, 1928 2109124502 Edwlaz'fi. @022,

Patented Nov. 1, 1932 UNITED STATES,

PATENT OFFICE EDWIN RUDOLPH Gm OI WIIBLEDON, IDRDOR, ENGLAND I mime INCANDESCENT LAM P AND HOLDER THEREOF I Application fled December 5, 1988, Serial Ilo. 828,949; and in Great Britain December 18, 1H7.

This invention relates to incandescent electric lamps'of the kind c'omprisin afilament extending lon 'tudinallyo an. e ongated tu- Jular bod uch lam s are especially adapted for illuminating o jects from concea ed points and for this purpose are usually assembled in line in a channel or like shaped reflector,v the lamps being secured in and supplied with current through holders engagmg lateral contacts shown in the form of metal caps on the lamp bodies.

The object of the present invention is to provide an improved construction of tubular electric lamp and holder therefor enablin a more uniform distribution of light an a higher degree of illumination to be obtained than heretofore.

According to the present invention the lamp contacts are in the form of metal caps disposed laterally of the lamp body instead of at the ends and the filaments are carried to the ends of the glass lamp bodies so that the filaments of adjacent lamps may be brought more closely together within the reflector. The lamp holder for use with thisimproved lamp comprises recessed contact devices adapted to receive the laterally disposed conreference will now be made to the accompany- I ing drawing, which illustrates a lamp and lamp holder constructed according to the invention, wherein Fig. 1 is a side elevation of the lamp.

Fig. 2 is a transverse vertical section thereof, taken on the line 22 of Fig. 1, 49 Fig. 3 is a front elevation, with parts broken away, showing two lamps in position in a lamp holder,

Fig. 4 is a transverse vertical section on the line 4-4 of Fig. 3 and Fig. 5 is a similar view on the line 55 of Fig. 3.

As shown the lamp comprises a tubular glass body 1 terminating in substantially hemispherical end walls 2 and a filament 3 extending longitudinally of the body and into close proximity to the end walls thereof, said filament bein supported at intervals by wires 4 projecting mm a common glass tube or rod 5 mounted within the tubular body 1.

The filament supporting wire 40 at each is end of said tube 5 is inclined towards the adjacent end 2 of the lam body in order to support that portion of t e filament 3 which extends beyond the corresponding end of thev tube 5 to the supporting and current conduct- '0 ing wire 6. r

In order that a sufiiciently' rigid support for the filament ends ma be aflorded by said wires 6 the latter are each wound around one of the supports 7, provided to position the I6 glass tube 5 within the lamp body, before be ing led out through a seal-point 8 formed laterally of the body 1 near the respective end thereof. These-seal-points are covered with metal contact caps 9 to which the leading-in 7 wires 6 are attached.

As shown more clearly in Fig. 1 the supports 7, which are preferably formed of steel or other resilient wire, are each connected at one end to the glass tube 5 and are secured to the wall 2 of the lamp body at the other end by means of a glass bead 1O fused on the wire 7 and to the inner surface of said wall 2.

On the side opposite the contact caps 9 shallow depressions 11 (Fig. 2) may be formed in the glass wall of the lamp body 1 to facilitate the engagement of the lamp in its holder and its subsequent retention.

The improved lamps made in accordance with this invention may be mounted in line with their end walls 2 in close proximity and, as each filament 3 extends practically the whole length of its lamp body, a substantially continuous line of luminous filacontact caps 9 and spring tongues or fingers adapted to press the lamp body towards said contact devices.

The channel shaped reflector 12 of known form is provided at appropriate points in its length, spaced to correspond to the distances apart of the contact caps 9 on the lamps to be held therein, with contact devices 13, 13a disposed adjacent one edge of the reflector. Said contact devices, as shown, comprise blocks of metal secured to arcuate strips 14 of insulating material at those ends thereof which pro'ect into the channel of the reflector 12 throug apertures 15 formed in said reflector.

Screws 16, which secure the insulating strips 14 in position transversely of the reflector and at the rear thereof, also serve to secure spring clips or tongues 17 on the front face of the reflector in such position that the bends 18 in the spring clips may engage in the recesses or shallow depressions 11 formed in the lamp bodies 1.

Each lamp is secured in position in the reflector by means of a pair of contacts 13, 13a and a pair of spring clips 17 co-acting therewith. One of each pair of contacts, as for example 13, is formed with a central conical recess 19 to receive one contact cap 9 (see Fig. 4) whereas the other contact 1311 of the pair is formed with a V-section groove 20 directed parallel with the axis of the lamp (see Fig. 5) within which groove the other contact cap 9 is received.

This arrangement allows for the longitudinal expansion which occurs in the lamp body, the contact cap engaged in the groove 20 being capable of sliding along said groove without dislodging the lamp.

It will be seen by reference to Fig. 4 of the drawing, that in positioning and supporting the lamp bodies with respect to the combined holder and reflector, as hereinbefore described, the filament in the lamp body will be correctly located at the focus of the reflector.

It will be understood that appropriate connections may be made to the contacts 13, 13a in order to supply the lamps with current and that the depressions 11 formed in the side of the lamp body remote from the contact caps 9 may in some cases, be disposed intermediate of the contact caps instead of exactly opposite the latter.

I claim 1. An incandescent lamp comprising an elongated glass bulb having exposed hemispherical ends, an enlongated glass supporting rod extending longitudinally within said bulb adjacent a wall thereof and anchored at the ends of the bulb, filamentcarrying posts projecting from said rod at points spaced apart along its length, a filament carried by said post extending longitudinally within the bulb and into the hemispherical ends thereof, and lateral contacts onthe bub electrically connected with the ends of said filament, said bulb having shallow sockets on the side thereof opposite that carryin said lateral contacts, said sockets being a apted to receive spring detents.

2. An incandescent lamp comprising an elongated glass bulb having hemi-spherical ends, an elongated glass rod extending longitudinally in said bulb near one side thereof, the ends of said glass rod terminating short of the hemi-spherical bulb ends and being rovided with supportin wires which proect longitudinally there om well into said hemi-spherical bulb ends, means securing said supporting wires to said bulb ends, posts carried by and projecting laterally from said glass rod, the endmost of said posts being directed obliquely beyond the ends of said glass rod, lateral contacts on said bulb, conducting wires extending from said contacts into the bulb, said conducting wires being Wrapped around said supporting wires and having projecting terminals well within said hemi-spherical bulb ends, and a filament secured at its ends to said projecting terminals of said conducting wires and secured at spaced points to said points.

In testimony whereof he has aflixed his signature.

EDWIN RUDOLPH GROTE. 

